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(SART) Search & Rescue Transponder

  • Sanatan 
  • 5 min read

The Search and Rescue Transponder (SART) is a self-contained waterproof transponder for emergency use at sea. These devices can be SART radar or GPS-based AIS-SART (SART Automatic Identification System). The SART radar is used to locate a lifeboat or ship in distress by creating a series of points on the rescue ship. Radar screen. SART will only respond to 9 GHz X-band sart-2 radar (3 cm wavelength). It will not be visible on the S-band (10 cm) or other radars. The Global Maritime Distress and Safety System (GMDSS) onboard contains one or more search and rescue positioning devices.


All boats with a total weight of 500 GRT must carry at least one SART. Vessels greater than 500 GRT must carry at least two SARTs. The

A SART receiver can detect signals from X-band radars (9.2-9.5 GHz). If SART detects a signal, it will immediately response with twelve pulses at the same frequency. The radar sees this signal as an “echo,” which will be displayed on the screen as a series of twelve points with a distance of 0.6 miles between them. The first point is at the SART position, and the other points directly reach the edge of the screen.

If the rescue ship approaches SART, the twelve points will become short arcs. As the ship approaches, the size of these bows increases. If the rescue ship is very close, the SART will be permanently activated by the side lobes of the radar antenna. The SART signal will be displayed as twelve complete circles on the radar screen. This will tell the search and rescue team that they have arrived more or less.

How Search and rescue radar transponders (SART) is needed in ships?

  • On both sides of the ship Search and rescue radar transponders should be installed, preferably visible from the bridge. It is easy to bring the transponder to a lifeboat or raft. It is recommended to be in a visible position near the door inside and outside the cab. It can be used in emergencies. The SART should be equipped with a pole or other equipment compatible with the survival craft antenna cavity to reach the required height at least 1 m above sea level.
  • On ships equipped with at least two radar transponders and equipped with a free-fall lifeboat, one of the radar transponders should be stored in the free-fall lifeboat and the other should be stored near the navigation bridge so that it can be used for boarding. And get ready. Transfer to any other survival craft.
  • The SART must be marked for waterproofing, with operating instructions, battery expiration date, ship name, and call sign.

SART – General features, location, and functioning

  • SART is made of fiber-reinforced plastic, which can withstand and be exposed to sunlight and extreme weather conditions for a long time.
  • Able to float out of the lifeboat
  • International Orange
  • SART is installed on a fixed support, which is fixed on the ship’s bulkhead, on the bridge
  • It operates in the 9 GHz frequency band (9.2 at 9.5 GHz) and works on A series of fragments (3 cm / X-band radar) are generated on the radar being interrogated.
  • Can be portable or permanently fixed on the lifeboat
  • SART is activated manually and therefore only responds when interrogated
  • When activated in a distress situation, SART responds to radar interrogations by sending a signal, which is generated on the radar by 12 acoustic signals and, as the distance between them decreases, they become concentric circles
  • In PPI, the distance between light signals will be 0.6 miles
  • This signal is easier to detect than the echo from the

radar reflector. SART also has audio or visual instructions to tell it to operate correctly and notify survivors when radar prompts When radar is not visible, a beep will be heard every 12 seconds; when requested by the radar, a beep will be heard every 2 seconds.

Carriage Requirement

  • Passenger ships: at least 02
  • cargo ships of 500 GT and over, at least 02
  • cargo ships of 300 GT and over, at least 01
  • 1 in each lifeboat

Battery Requirement

  • In the standby state, it can run for 96 hours
  •  In the working state, it can run for 08 hours
  •  Every 2-to-5-year battery should be changed
  •  can run in the temperature range of -20 degrees to 55 degrees

SART Test procedure

Self Test (General)

  • Switch SART to test mode
  •  Hold SART
  •  according to radar antenna Check if visual indicator works
  •  Check if the buzzer works
  •  Observe radar screen and check for concentric circles on PPI
  •  Check date battery expiration

Self Test (General)

  • Remove the SART from the bracket
  •  Insert the probe into the SART within 2 seconds. The indicator light flashes and the buzzer sounds
  •  Observe the concentric circles on the X-band radar.


 AIS-SART is a piece of standalone radio equipment used to locate lifeboats or ships in distress by sending up-to-date position reports using type A position reports from the standard automatic identification system. The AIS-SART time and position synchronization come from the built-in GNSS receiver (like GPS). The Global Maritime Distress and Safety System (GMDSS) installation includes one or more search and rescue positioning devices.

SART can be used in rescue operations involving aircraft or ships in air and maritime accidents. They are designed to survive the harshest conditions and remain active in higher positions (such as on poles), so they can cover a variety of areas. Speaking of altitude, the range of a SART transponder on an airplane can be 30 to 40 miles. This helps to check the wide range and area carefully.

 Based on the facts, SART can be determined to be a miracle of ergonomics, making it an important device for navigating the deep sea.

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